In seated twists like this one, it's important to sit up tall and focus on lengthening your spine before you begin to twist. Done correctly, spinal twists increase circulation and build strength and flexibility in your back muscles. But you must be warmed up properly before you perform them.

—Karen Voight

A. Sit on the floor with both legs straight in front of you. Bend your left knee and place your left foot flat on the floor in front of your left sitting bone. Bend your left elbow and place it on the inside of your left knee with your fingertips pointing upward. Place your right fingertips on the floor behind you to help you sit upright. Inhale, lengthen your spine, extending through the crown of your head. On an exhale, rotate your ribcage, chest, shoulders and head to the right – don't allow your left knee to flare out to the left (keep it pointed up to the ceiling). Pause for three full breaths.

B. When you're ready to intensify this twist, wrap your left arm around and behind your left leg and move your right hand to grasp the fingers of your left hand. Keep your shoulders relaxed and press down with your left foot as you continue to lift up through the crown of your head. Stay here for three to six deep, full breaths, then slowly release and repeat on the other side.

Voight is the creator of a line of fitness DVDs, including "Sleek Essentials."